WO 2009/086643 describes a wearable sensor device for determining a physiological parameter of its wearer, such as glucose level. It comprises a housing with a set of electrodes arranged at its bottom side. A wristband is attached to the housing for being wound at least once around an arm or leg of the wearer and for attaching the housing with its electrodes facing the wearer's skin.
A similar device is disclosed in WO 2007/053963, which, in addition to electrodes, comprises optical sensors and temperature sensors, also to be worn against its wearer's skin. Again, the housing of the device is held by means of a wristband against a body part of the wearer. The device can e.g. be used to measure glucose level, blood perfusion, or surface water content.